Introduction:

Gingival hypertrophy (GH) is the increase in the volume of the gingiva associated with certain systemic, hereditary (idiopathic) diseases, the intake of some medications or local factors such as orthodontic treatment, capable of causing histological changes in the gingival connective tissue.

Objective:

To describe the histological characteristics and identify type I and type III collagen in gingival tissues of subjects with gingival hypertrophy wearing orthodontics.

Method:

A case-control study was designed that included the analysis of gingival tissue biopsies from 12 patients submitted to periodontal surgeries. The sample was divided into two groups: healthy individuals (Control; n= 6) and patients with GH wearing orthodontics (Patients; n= 6). The samples were processed and embedded in paraffin. Masson-goldner and sirius red/fast green stains were used. Type I and type III collagen were identified by immunohistochemistry with monoclonal antibodies.

Result:

A hyperplastic epithelium and dense connective tissue with abundant randomly distributed collagen fibers were observed in patients with orthodontic GH. Immunodetention of type I collagen indicated the presence of abundant disorganized fibers and type III collagen was inmunolocalized underlying the basement membrane, blood vessels and the entire extension of the connective tissue of patients with GH orthodontic.

Conclusion:

The accumulation of collagen fibers, particularly type I and type III collagen, are histological findings that characterize GH in orthodontic wearers. Future studies are necessary to elucidate the phenotype of gingival fibroblasts and the probable homeostatic loss between collagen production and degradation in this pathology.